Lotta Bull

I love nature programs on television, and in particular, can’t get enough on the social lives of lions and elephants. My only complaint is that most of the shows pay too little attention to the males. The adult females, understandably enough, seem always to be in the thick of things, leading the group, finding food, rearing the young, communicating with one another and organizing everything. Whereas male lions, for example, seem to spend all of their time alone and out of sight, patrolling the territory, leaving scent marks, and occasionally roaring at other adult males who might be contemplating an invasion.

But now comes a wonderful study on adult male elephants, recently reported in Nature magazine. Between 1992 and 1997, 17 young, orphaned male elephants, whose parents had been killed in herd cullings, were relocated to a park in Pilanesberg, South Africa. They promptly started acting, well, wild. In particular, they went into musth - a hormonally induced state of heightened sexual and aggressive activity - earlier than is normal, and for longer periods of time than is normal. As a result, the young males stormed around the park, quite out of control, killing about 40 white rhinoceros in the process.

Then, in 1998, the people who run the park relocated six older bull elephants from Kruger Park to Pilanesburg. The “deviant behavior” of the young males, the researchers report, was quickly “rectified.” No more rampaging, no more dead rhinoceros. What happened? Specifically, there occurred a significant reduction in musth in the young males. Put colloquially, their hormones calmed down. And why did this occur? More research is needed, but it seems clear that old bulls keep young bulls in line, and that exactly how this happens involves both social and physiological factors.

Of course, none of this has anything directly to do with human beings. However, apart from my silly, anthropomorphic desire to identify with the big bulls, I am struck in this regard by new research findings, published in the journal Evolution and Human Behavior, showing that new and even expectant human fathers living with the mothers experience significant hormonal changes that “may play a role in priming males to provide care for young.” (The same phenomenon seems to occur in other biparental species - that is, species in which couplings are largely monogomous and in which both parents help to raise the young.) I am also struck by two recent studies (I wrote about them in letter 8) showing that human fathers residing with their daughters slow down the onset of their daughters’ puberty, or sexual maturity, whereas the close proximity to young girls of unrelated males, such as stepfathers or mothers’ boyfriends, actually speeds up the onset of puberty. 

It seems that we are only beginning to understand the complex relationships, involving chemicals and hormones as well as communications and social behaviors, between adult and juvenile members of the same species. But while we are figuring all this out, old bulls, take heart. You too have a role in life.

Sources: Rob Slotow, Gus Van Dyke, Joyce Poole, Bruce Page, and Andre Klocke, “Older bull elephants control young males,” Nature 408 (November 23, 2000): 425-426. Anne E. Storey, Carolyn J. Walsh, Roma L. Quinton, and Katherine E. Wynne-Edwards, “Hormonal correlates of paternal responsiveness in new and expectant fathers,” Evolution and Human Behavior 21 (2000): 79-95.

First published Winter 2001.